


Twin Skeletons (Horsebow Moon)

by MxMearcstapa



Series: Lunar Haruspex: A Blue Lions Story [6]
Category: Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Angst, Animal Death, Battle, Body Horror, Character Death, Death, Divine Pulse (Fire Emblem), F/M, Feelings Realization, Other, Possibly Unrequited Love, Sharing a Body, Spoilers, Time Travel Fix-It, Training, no beta we die like Glenn
Language: English
Status: Completed
Published: 2019-12-29
Updated: 2019-12-29
Packaged: 2021-02-27 07:20:25
Rating: Mature
Warnings: Graphic Depictions Of Violence, Major Character Death
Chapters: 1
Words: 4,264
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22013239
Author URL: https://archiveofourown.org/users/MxMearcstapa/pseuds/MxMearcstapa
Summary: In the late Horsebow Moon of 1180, the mood at Garreg Mach was frenetic. Flayn, the younger sister of the Archbishop's assistant, had been missing for weeks. The monastery had been combed once, twice, thrice over with no success. Noticing her students snapping at each other, Byleth took them out to train.Following Byleth/Dimitri B, in which the house leader of the Blue Lions learns he is more fond of his professor than he realized, and Byleth demonstrates that she would die before letting her students be harmed and that having an amnesiac gremlin in your head ain't easy.
Relationships: Dimitri Alexandre Blaiddyd/My Unit | Byleth
Series: Lunar Haruspex: A Blue Lions Story [6]
Series URL: https://archiveofourown.org/series/1584496
Comments: 13
Kudos: 138





	Twin Skeletons (Horsebow Moon)

**Author's Note:**

> ***Update 6/8/20***  
> The first part of this series is finally posted! And the gap between that piece and this one is pretty long, but I'm working hard to fill the gap!  
> ***
> 
> This is intended to be near the beginning of the middle of a longer series, but I had a BURNING NEED to post it now as is. 
> 
> Hopefully it pleases someone. 
> 
> Setting is Horsebow Moon, when Flayn is missing, after Dimitri and Byleth achieve a B-support.

The sky was alight with dragonflies.

In the late Horsebow Moon of 1180, the mood at Garreg Mach was frenetic. Flayn, the younger sister of the Archbishop's assistant, had been missing for weeks. The monastery had been combed once, twice, thrice over with no success. Byleth and her students had conducted one of several investigations and come up with nothing. Whispers. Rumors. Wild accusations. Trusted allies cast into suspicion. Not even Sothis had any insight. And so far, all had been for nothing--no answers, no leads, and no Flayn. Noticing her students snapping at each other, Byleth took them out to train. Early in the morning, she roused them, bid them to change into something they didn't mind sweating in, and led them out, away from the monastery, with nothing but a few training weapons and a basket of snacks. Byleth did, however, take the Sword of the Creator. Even for a simple training exercise, it felt strange to part with the weapon that so fiercely resonated with her. Though her students grumbled loudly at the hour, their eagerness was obvious. And, the farther they got from the monastery, the more the mood improved.

At least, until the training started in earnest. As her students ran laps, Byleth watched the dragonflies circle overhead, bright greens and blues iridescent against the late morning sky. There were dozens of them, ducking and weaving, snatching bugs out of the air. Almost like a plague of locusts, blotting out the sky. Between the dragonflies' speed, dexterity, and sheer numbers, their prey stood no chance. It was a one-sided battle, elegant and brutal. Byleth couldn't decide if she found it beautiful or frightening. Perhaps a little of both.

"Professor?" A voice pulled her attention back down to the earth. "Is everything alright?"

Dimitri stood in front of her, doubled over and panting. He looked up again and smiled like sunlight. As usual, he was first to complete the laps, and almost glowing. The exercise suited him. It suited them all, really--the chance to get out and do something actionable, something with meaning--but Dimitri seemed the most visibly pleased. Byleth felt warmth spread through her at being able to improve the mood, even if only a little. She looked past Dimitri to gauge how her other students were faring. Felix was the nearest to crossing the finish line, followed closely by Ingrid and Ashe. Dedue kept at a steady pace, but Sylvain outmatched him with a laugh and a wave. Behind them, Annette urged Mercedes onward, but the healer looked to be in no hurry.

"It's funny," Sothis said inside her head. Byleth could hear the smile in her voice. "How long have you been referring to them as 'your' students? I recall a time when you could not remember their names."

That was true. For a time, she had given the students nicknames to tell them apart (and she hoped to keep those nicknames a secret to her grave). But that was before. They _were_ her students now. In the nearly half-year they had spent together--eating, training, learning, sparring, supporting each other in battle and heart--she had come to know them and their quirks. What they liked to eat, what they liked to read, their hopes and dreams, their strengths and weaknesses. She knew who wouldn't turn down seconds at mealtimes (Ingrid and Annette), who most often volunteered to cook (Ashe and Dedue), who was always at the training grounds latest (Dimitri and Felix), who was least likely to turn in the assignments she gave (Sylvain and Mercedes), and who was most likely to be prepared for pop quizzes (none of them, bless their hearts). They were hers, and the realization bloomed warmly in her chest. She was theirs, too, and she hoped they felt the same. That they might not sent an icy chill through her. Peals of laughter from Sothis echoed through her head.

"Professor?" Dimitri had moved closer. She saw the concern in his bright blue eyes and shook her head, testing a smile. Dimitri arched his eyebrows, apprehension still apparent, and Byleth let the smile fall. She had made the wrong face then. Smiled too wide? Not wide enough? Or was it her eyes? It was hard to tell when she was making the right face, but it was getting easier. At least, it seemed to be. Mostly.

Words would have to do, then, though she felt inept with those, too. "Everything is fine, Dimitri. I was watching the dragonflies." She pointed upwards, and he followed her hand. When he saw them, he inhaled sharply.

"There are so many," he breathed. "Aren't they dazzling?"

It was acceptable to find them beautiful, then, even as they slaughtered? Byleth looked at Dimitri, but he was transfixed on the insects above. With his attention preoccupied, she studied him. His face was red from the exertion of jogging but returning to its usual paleness. He had been burnt all summer, but never tan. Did living your whole life in a land as cold as Faerghus render you permanently that pale? The bags under his eyes, from late investiagtions and postulations on Flayn's whereabouts, were dark and puffy. With only a slight twinge of guilt, Byleth wished she had let the students sleep in some instead of pulling them out so early this morning. But the smile on Dimitri's face as he watched the skies above was worth it. The cool mountain breeze, the splendor of the sunlight on the greenery--it all paled in comparison to seeing him relax. And after what he had said last night...

_"Now I know, with all my heart, that I can trust you."_

She couldn't let him down.

"Perhaps they are a good omen," Dimitri continued, still gazing skyward. "That we will find Flayn soon. Ah, but...forgive me. The answer is not likely to be in the skies."

Felix completed his final lap and passed in front of them. He glanced upwards, then scoffed. "Never seen a bug before, Boar?"

"Felix," Byleth warned as Dimitri smiled and looked down. Sylvain passed in front of them and rolled to the ground with a groan. Ingrid arrived shortly behind him, already chiding Sylvain about proper cooldown techniques.

"It's alright, Professor. He's right. We ought to be focusing on training. Becoming dragonflies ourselves." Dimitri smiled again, though it was less bright than before. Byleth felt her chest tighten. She grasped for words.

"You are already as fierce as lions," she mumbled.

Dimitri blinked in surprise, the corners of his mouth turning up again. "Professor--"

"Boar!" Felix shouted from nearby. "Wipe that dumb look off your face and come spar with me."

* * *

When the professor had woken them so early in the morning, Dimitri feared the worst: that Flayn had indeed been found, and less than whole. When it became apparent the disturbance was unrelated to Flayn, Dimitri was as relieved as he was frustrated. Every day that passed without finding the girl set his teeth further on edge. What use was all that training, all the strength he gained, if it couldn't help to save a life?

Dedue was quick to point out to him that they were doing everything in their power--and that was somehow worse. All they were doing--the late nights, the patrols, the interviews, the evidence-gathering--none of it was enough to find Flayn. She had been missing almost a full month. It was hard not to lose all hope.

As he stumbled with the rest of his classmates behind the professor in the early morning, arms full of wooden training weapons, Dimitri worried. How could they find Flayn out here? Surely it was better to be back at the monastery, poring over the clues they had, no matter how few. He was fortunate that someone else had asked the professor first.

"Pardon me, Professor, but...how--" Ashe's reedy voice cracked, and he cleared his throat. "Uh, how will this help find Flayn?"

The professor shook her head. She must have seen the confused looks on her students' faces, as she blinked several times in rapid succession and then said, "We're not out here to look for Flayn."

"Well, why not?" Annette asked. "It's not like she's going to find herself. Not after this long..."

"As though she'd come waltzing back unharmed. What a foolish thing to say." Felix crossed his arms.

Annette balled her hands into fists at her sides. "Like that's really--"

"That." The professor said more loudly than they had ever heard her speak, and they jumped. She paused, then continued softly, "is why we're out here. Pair up and grab a weapon."

The training was relentless. They practiced with weapons they were unskilled with until they could wield them without feeling awkward. With the weapons they were proficient with, the professor drilled them harder. She had them practice magic, healing and harming both. They exercised, repetitions of cardio and muscle-building motions set to the steady cadence of her drumming a lance against the earth. Between activities, they stretched, as much to relieve muscle tension as to push their flexibility. By the time she had them running "cooldown laps," every single student was drenched with sweat.

It was the best Dimitri had felt all month. His body ached, his lungs burned, his limbs were jelly, and he loved it. He felt jubilant. He had to thank the professor--she had seen them struggling with the lack of forward motion and known how to remedy it. As he finished his final cooldown lap, Dimitri approached her. When he saw her gazing into the air, lips parted, he stopped. He should say something. It wasn't right to stare. But she looked so mesmerized, the wonder plain on her face, that it struck him. It was such a far cry from her usual stony expression. A sight so rare that he wanted to savor it for just a moment longer before--wait, savor? Dimitri was glad he was probably red from exercise so no one could witness him flush with embarrassment. It was true that the professor hadn't been the most expressive when they first met, but she seemed more expressive every day--or had he simply learned to read her? And it shouldn't have mattered anyway, because he knew from months of speaking with and battling alongside the professor that her outer expression did not often match her inner feelings.

And besides that, he was staring.

"Professor? Is everything alright?" He asked. She started and blinked at him, eyes wide with surprise. He smiled at her, inwardly fascinated at catching her unawares. Something unreadable crossed over the professor's face as she focused on him. Almost like...warmth? Was it really unreadable, he wondered, or just unfamiliar on her? Regardless, it was no less intense than the way she always looked at him. At all of them, he reminded himself. Dimitri tried not to shiver. It was like his soul was being bared before her. She looked past him without a word, and the chill passed.

"Professor?" He hazarded to speak, both afraid to receive and hoping for her intense gaze again. She turned to him and smiled radiantly, shaking her head. Dimitri clenched his fists together. _That smile could burn an empire,_ he thought. The professor was beautiful, even in her austerity, and the realization that he felt so terrified him beyond words. This was not an okay way to feel. It was not okay to think.

The light in front of him went out, and he heard the professor say, "Everything is fine, Dimitri. I was watching the dragonflies."

She pointed above them. The sky glittered with the wings and speeding bodies of scores of colorful dragonflies. Dimitri felt his breath catch.

"There are so many. Aren't they dazzling?"

The professor looked at him sharply, and Dimitri stared stiffly up at the sky. It was beautiful, to be certain, and with the professor so near and his thoughts so muddled, it was easier to look at the dragonflies than at her face. Dimitri resolved to look up until he could get ahold of himself. With the heat of the professor's gaze roaming over him, it was difficult.

 _Fool_ , he reprimanded himself. _You're supposed to be thinking about finding a lost girl. You can't afford to distract yourself so. You are misinterpreting and overreacting._

 _But_ , another part of him thought with a softness, _what does it matter if I find her...pleasant to look at? She is a pleasant person. Last night...she listened to my silly concerns with more patience and kindness than I could ever have expected. She is still my professor, and I her student. Nothing changes that._

It still felt wrong, though. Dimitri felt a dull ache spread through his chest. How long had he been staring upwards now? Probably too long. He needed to focus.

Licking his lips, he spoke, "Perhaps they are a good omen. That we will find Flayn soon. Ah, but...forgive me. The answer is not likely to be in the skies."

Footsteps signalled Felix's approach. Dimitri caught the cold look in his friend's eye as he looked between Dimitri, the sky, and the professor.

"Never seen a bug before, Boar?" He quipped on his way over to the training weapons. Dimitri felt the words like a dagger in his heart. _Oh, Felix. I deserve worse, and you know it._ There was nothing to be done for it now. He smiled.

"Felix," the professor scolded, and Dimitri felt a little of the ice inside him thaw.

"It's alright, Professor. He's right. We ought to be focusing on training." He smiled wryly and glanced up. "Becoming dragonflies ourselves."

The professor clutched a hand to her chest and fixed him with such a powerful, pleading look that Dimitri felt the breath knocked out of him. "You are already as fierce as lions," she said.

With a numbness, Dimitri felt his lips moving, tingling with what he was about to say. "Professor--"

"Boar! Wipe that dumb look off your face and come spar with me," Felix demanded, brandishing a wooden sword.

Oh goddess. Were his thoughts obvious to even Felix?

* * *

It wasn't the roar that sent Byleth running across the field--it was Annette's scream. The whoosh of a fire ball and the cutting whips of sudden wind. Sylvain's stream of curse words. Mercedes calling her name. Byleth was moving towards the fighting before she had even removed the Sword of the Creator from her side. Felix and Dimitri had begun to spar. They were closer, but they stood still, startled by the sound. Byleth called to them as she ran past.

A demonic beast. It towered over her students, pale and scaled, reeking of the bitter poison of its breath. If they were equipped with proper weapons, if they had their battalion squads or their mounts--goddess, if the students were even _armored_ , it would have been a different situation.

A heavy clawed hand came down on Annette's body, and Byleth screamed as it pressed the girl into the earth. She did not remember drawing the Sword of the Creator, only that it was red and glowing in her hands. She allowed herself only one strike out of anger and then quickly surveyed the field.

Dimitri, Felix, and Sylvain flanked the beast. They shared a look and nodded before launching an offensive. An arrow whizzed past Byleth's head and buried into the leg that had pushed down Annette. Mercedes stood further back, tears streaming down her face as white light erupted from her hands.

"Their weapons are only made of wood! They cannot do much for long!" Sothis said.

"Get back!" She commanded as the beast lifted its bloody claw to swipe at Felix. He was fast, but the morning of intensive training had slowed him just enough to be caught. Streaked with red, he collapsed. Sylvain called to him in a strangled voice.

 _No_.

The world pitched and shattered violet. She stepped back and back again. Felix rose, flesh knitting together and wounds closing. The arrow returned to Ashe's bow. The beast's claw leeched blood and lifted Annette up as she absorbed a green blast of wind. Backwards, the beast walked into an outcrop of rocks into the mountains. The dragonflies buzzed in reverse.

 _There_.

The world resettled. Byleth's hand was pressed to her chest.

"Professor--" Dimitri began.

She would have to ask him what he meant to say later. Now, she was hurtling towards Anette, Sylvain, and Mercedes near the edge of camp.

"Boar! Wipe that dumb look off your face and--"

"Dimitri, Felix, on me, _now_." Byleth didn't check to see if they were following. She knew they would be. More loudly, she called, "Anette! Mercedes! Sylvain! This way, _immediately_!"

Her mages looked back, confused, but complied, slowly making their way towards her. When they saw her sword out, and the boys behind her running towards them, they picked up the pace.

"Not fast enough!" Sothis chided, the desperation in her voice clear.

From behind a craggy corner, the beast appeared. It let out a mighty roar, and Byleth let out her own roar to meet it.

The battle itself was a blur. Byleth had been ready to take the beast on alone, but at some point her students had come to help, and they were working together. She was filled with equal parts pride and terror. One of the students--it looked like Dimitri--thrust a weapon into one of the beast's legs, and it crashed to the ground with a frightened scream. Byleth slashed at its exposed underside, and it was over.

"Is... is everyone okay?" The world was red and unsteady. Byleth wiped her eyes, straining to count her students. They were shaken and a little bloody, but all eight were standing.

"That was far too close," Sothis breathed as Byleth tried to catch her breath.

"Who needs to be healed?" She asked. Felix harrumphed, but when Ingrid gripped his arm, he grunted in pain. Dimitri was staring at her, blood dripping from his shoulder.

"Professor, are you alright?" Mercedes asked, hands clutched tightly together.

"I believe we are free of injury," Sothis informed her. Byleth nodded too many times as various other students asked for confirmation.

"This blood is not mine," she told them. "Pair up. Heal like we practiced."

The air around them was suffocating, drenched with acid and iron. Byleth left her students as they settled into their healing routine. She could not begin to find a word that expressed her feelings that she had insisted they learn white magic. So much tragedy and uncertainty avoided due to a single idea. By their willingness to follow her.

Byleth found she had walked away, over to the corpse of the beast. Why had it come here? Now it was nothing but a steaming mass of flesh. As it smoldered, she was reminded of a memory.

She was younger, and out alone. She was searching for something, but what it was she could not recall. From behind a building, a demonic beast had come at her, eyes wild and fangs bared. She remembered not fearing for her life, only feeling an incredible sadness--

Byleth wobbled and touched a hand to her head.

"Whose memory was that?" Sothis demanded. Byleth had no answer for her. In her chest, the sadness lingered, oppressive. In the back of her throat, the burning sensation of bile. She knelt into the fog of the beast's decaying body to touch the bones therein.

How could they be so small? How could they look so worn for so recent a death? Something swelled in Byleth, and she collapsed over her knees.

* * *

"Professor, you are beautiful," is what his dumb, dazed brain might have gotten past his lips if the professor had not broken into a sprint. For half a horrified moment, Dimitri feared that she knew what he was going to say and ran before she would hear it.

Then he saw her draw her sword and commanded he and Felix follow, and his fear soured into something darker. He grabbed a training lance from the ground and followed her without question.

Near the rocky foot of the moutain, Sylvain, Annette, and Mercedes had been practicing their magic. There was nothing near them that suggested a threat, but the professor bid them to her all the same, running like their lives depended on it.

When the demonic beast rounded the corner, Dimitri was surprised. What was it doing so close to the monastery? They had never been sighted here before. His confusion bloomed in tandem with his awe as one question repeated more loudly than the others: How had the professor known it was approaching? The beast screamed, and the professor screamed back and leapt at it with a mighty swing of her sword. The golden arc of her blade was echoed by a dark spray of rust. The professor bounced backward and spun, grunting into another slash. She danced between the beast's grasp, every step drawing blood.

Dimitri felt his pulse in his ears.

She was breathtaking.

Felix appeared at his side and shoved him, snarling, "Go left--she can't do it alone. I won't let her. We'll flank."

Felix was right _again_ , and Dimitri stuffed the guilt and embarrassment down deep as he moved into position. Such a failure could have cost the professor's life, and he had just been _staring_. He was going to need to unpack these feelings at another time. Now, he needed to focus. He met Felix's eye from across the beast. Though Dimitri couldn't hear Felix's contemptuous grunt, his expression was clear.

"Now, Dimitri!" He heard Sylvain shout. The beast turned towards Sylvain's fireball, exposing the back of its leg. Dimitri dove towards it, thrusting into the joint where the leg met the body. The Crest of Blaiddyd boiled in his blood and pushed the lance farther in.

With a high-pitched shriek, the beast sunk on its damaged limb and writhed.

But then its stomach was exposed.

With a flash and a yell, the professor sliced into the exposed flesh, and the beast went still.

"Professor!" he heard Mercedes cry. "Are you alright?"

"Is...is everyone okay?" The professor asked, wiping blood from her eyes. She was looking around more frantically than Dimitri had ever seen her look. The utter lack of composure unnerved him. He was not used to this professor. "Who needs to be healed?"

The Blue Lion house gathered closely, checking each other for wounds. Miraculously, no one was critically injured. A few scrapes, one bad claw on Felix's forearm, and a cut Dimitri hadn't remembered getting on his shoulder. All things that could be mended with magic. Their professor insisted she was fine, claiming the blood that coated her was not hers, and from what he could tell, that was true. Yet another miracle.

In pairs, the students sat together and healed each other. Dimitri was grateful that she had encouraged them all to learn a little healing magic early on. Perhaps she had known moments like this would be common, or perhaps her life as a mercenary was often fraught with injury. In any case, it was a good thing and aided them greatly now. Composure returned, and satisfied that no one was worse for wear, the professor left them to finish healing and walked back over to the body of the beast. Steam rolled off it in waves.

Accompanied by an impassioned lecture from Dedue about putting himself so close to danger, Dimitri allowed his shoulder to be tended to. When the magic had done what it could, he cautiously approached the professor. She stood with her back to them, watching the beast evaporate into bloated, billowing white clouds. In minutes, it was gone entirely. Where it had been, there were only bones much too small to belong.

Dimitri had never seen a beast dissolve before--discounting Miklan, Sylvain's brother, who had been warped by the Lance of Ruin. But Miklan had transformed into a beast black as night, hadn't he? And when they had killed him, he had reverted to his human form, not a bizarre pile of bones. These didn't look like human bones, but they certainly weren't beast bones either. Not that he was by any means an expert.

He was dizzy with questions.

The professor knelt down and reached out a trembling hand to the bones. Her fingers brushed across one, and she folded over her knees, covering her face.

"Professor, what's wrong?"

Dimitri knelt next to her. He wrestled momentarily with the idea of touching her before deciding propriety be damned. He place his bare palm on her upper back and rubbed softly. With this gesture, he learned two things:

Firstly, as he touched her, a small sound akin to a sob escaped her. However, when she looked up at him, her eyes were dry and her gaze was hard. The hairs on the back of his neck stood up as she looked through him again with that soul-piercing gaze.

He felt distinctly, uncomfortably, for the first time, as though it might not be his professor looking back at him. This was not helped by the second revelation:

Even through her cloak, the professor's skin was cold. Not clammy and cool from the sweat of exertion, but cold. Too cold for covered skin in the sun.

"Professor?" He hazarded again. The hardness left her expression in an instant and her face twisted with fear.

Overhead, the dragonflies sped on.

**Author's Note:**

> In my circles, I am a known dragon sympathizer. :P I have a huge fixation on demonic beasts. I thought it would be cool if, upon death, their forms steamed away something like the titans in Attack on Titan, so I tried to touch on that. 
> 
> I also wanted to play on the idea that Sothis and Byleth are not quite as separate as the game suggests. Sometimes, perhaps, they share memories. Sometimes, perhaps a little more. 
> 
> For extra basic flavoring, title is inspired by Fall Out Boy song of the (nearly) same name (which is totally on this series' playlist). I, uh, recommend it.


End file.
